Answer
8, 4, 2, 1, 0.5 grams, respectively
Work Step by Step
After 25,000 years,
$ 16\cdot \displaystyle \frac{1}{2}=8$ grams remain.
After 50,000 years, ( another half-life)
$8 \displaystyle \cdot\frac{1}{2}=4$ grams remain.
After 75,000 years, ( another half-life)
$4\displaystyle \cdot\frac{1}{2}=2$ grams remain.
After 100,000 years, ( another half-life)
$2 \displaystyle \cdot\frac{1}{2}=1$ grams remain.
After 125,000 years, ( another half-life)
$1 \displaystyle \cdot\frac{1}{2}=\frac{1}{2}$ grams remain.
